In recent years, with the goal of energy saving or environmental conservation, a lighting apparatus using a light emitting diode (hereinafter also referred to as an “LED”) as a light source (for example, an LED bulb, an LED fluorescent tube, or the like) has been used as a lighting apparatus replacing a bulb, a fluorescent tube, or the like (refer to PTL 1, for example).
FIG. 1 is a diagram showing the configuration of lighting apparatus 10 according to PTL 1. As shown in FIG. 1, lighting apparatus 10 according to PTL 1 has light source 20 (a light emitting element) such as an LED, rod-shaped light guide member 30 which is formed of resin or glass and propagates the light emitted from light source 20, and optically-transparent cover 40 which covers light guide member 30. Light guide member 30 is disposed such that an end face (an incidence plane) thereof faces light source 20.
The light emitted from light source 20 is incident on the inside of light guide member 30 from the incidence plane. The light incident on the inside of light guide member 30 is emitted from the outer peripheral surface of light guide member 30 while advancing along an axial direction of light guide member 30, as shown by an arrow in FIG. 1, for example.